The objectives of this project are (a) to isolate and characterize two extracellular membrane associated glycoproteins and (b) to study their biosynthesis and assembly. The embryonal carcinoma-derived cell line M1536-B3 will be used for the studies. The experimental approaches will utilize both chemical methods and mutant cell lines. The techniques of somatic cell fusion will be used to obtain information on the control of biosynthesis and assembly of the glycoproteins into the extracellular membrane. The relatedness of the glycoproteins to basement membranes will be determined by immunological techniques.